Humans Could Evolve to Become Venomous

  • And you thought toxic people were bad now. Just you wait.

If you’re like 99% of humanity, you will know at least a couple of people you would describe as “toxic.” These kinds of individuals are pain to be around, but luckily you can in most cases get rid of them by just cutting them off.

But in the future, you might want to seriously steer clear of them. That’s because if evolution plays out just right, they might become literally toxic.

A new study, published in the journal Proceedings of the National Academy of Sciences, has found an interesting little tidbit about human genes. It turns out that we have potential to evolve into having venomous bites.

Granted, the likelihood of this happening is unlikely, but who knows? Maybe some kind of global cataclysm will force us back into the wilds, and people with nastier bites start surviving better.

“Essentially, we have all the building blocks in place. Now it’s up to evolution to take us there,” Agneesh Barua, a PhD student from the Okinawa Institute of Science and Technology and the study’s co-author, told LiveScience.

I wanna taste you but your lips are venomous poison. – Alice Cooper

Genetic Scaffolding

Venomous animals are nothing special when you look at the nature. Any number of insects, arachnids, and reptiles have venomous bites, some of them strong enough to even harm humans.

Even primates can have venom. The slow loris, which lives in Southeast Asia, secretes a substance in its bite that can cause painful swelling and, if you happen to be particularly allergic, could even kill you.

But the new study on which Barua worked didn’t actually study the toxins that various animals drool, spit, and inject from their mouth parts. Instead, they examined the evolutionary structures that helped them develop those abilities.

Barua calls these structures “housekeeping genes.” They aren’t directly responsible for creating toxins, but they are the framework on which biological venom-delivery systems are built.

“Since we know the function of all the genes that were present in the animal, we could just see what genes the venom genes are associated with,” explained Barua.

Toxic Lego Blocks

The research that Barua and her colleagues did produced some surprising results. They discovered that the genes responsible for venomous bites are common in all amniotes.

Don’t worry, even we had to look that word up. Amniotes are animals that fertilize their eggs internally or lay eggs on lands, including birds, reptiles, and some mammals.

Most interestingly, humans too have these same genetic structures. They have even produced some results – human salivary glands secrete a protein cocktail that helps break down food in our mouths.

These proteins, called kallikreins in science nerd circles, are also present in many animal venoms. Speaking in terms of evolution, there’s not a whole lot that’s needed for that system to turn into venom glands.

Kallikreins are highly stable proteins. That means that if the system that produces them starts mutating, the proteins don’t just cease to work.

“It’s not coincidental that kallikrein is the most broadly secreted type of component in venoms across the animal kingdom, because in any form, it’s a very active enzyme and it’s going to start doing some messed-up stuff,” Bryan Fry, a biochemist and venom expert at The University of Queensland, explained.

Fry added that after the nightmare that was 2020, humans might just want to start cultivating their toxic potential.

“If people need to be venomous to survive [after 2020], we could potentially start seeing increasing doses of kallikreins,” he chuckled.

Something for a Rainy Day

Luckily – or unfortunately, depending on how badly you want to have a toxic bite – it’s unlikely that we’d become venomous. For that to happen, we’d need some kind of complete collapse of current human habits of acquiring food and mating.

But what if something like that were to happen? Let’s imagine the kind of scenario where society is wiped out, 99.9% of humanity dies off, and we can’t rely on our ability to make tools anymore.

Should it come to that, catching food might become a bit difficult. We don’t have claws or fangs, and compared to many predatory animals, we’re not all that strong either.

That’s when particularly foul-mouthed people could start having an easier time catching prey after biting it. Over thousands of years, that could lead humanity on a path that ends in venomous bites.

The kind of venom we would develop is completely up to speculation, though. It would depend completely on what we’d be trying to catch in this situation.

In nature, the type of venom an animal has can vary wildly even within the same species. For example, some desert snakes living on the sand catch mice with a venom that attacks the circulatory system, while their brethren living in rocky outcrops catch lizards with a neurotoxin.

But the pieces needed to complete this venomous puzzles are all there. All that’s needed is a situation that forces our bodies to put them together in the right order.

Let’s test it out, shall we? Anyone got a spare doomsday device on hand?